Classic French Frangipane King Cake (Galette des Rois)

• 100 g soft butter
• 100 g granulated sugar
• 100 g ground almonds
• 1 whole egg
• 1 cap amber rum (optional)

Instructions

1. Prepare the pastry cream. Heat the milk in a saucepan with the vanilla, allowing it to gently infuse. In a bowl, whisk the egg yolk with the sugar and cornstarch until the mixture becomes pale and smooth. Gradually pour the hot milk over the egg mixture while whisking, then return everything to the saucepan. Cook over medium heat, stirring constantly, until the cream thickens and comes to a gentle boil. Once thick, remove from the heat, cover directly with plastic wrap touching the surface, and allow it to cool completely.
2. Prepare the almond cream. In a mixing bowl, work the soft butter and sugar together until creamy and well blended. Add the ground almonds, followed by the whole egg, mixing until just combined. Avoid overwhipping, as incorporating too much air can cause the filling to puff unevenly during baking.
3. Make the frangipane. Add the fully cooled pastry cream to the almond cream and mix until smooth and homogeneous. If using, stir in the rum. The finished frangipane should be supple, creamy, and easy to pipe. Transfer it to a piping bag for neat assembly.